Airfoil mechanism



Aug. 29, 1939. E. F. ZAPARKA AIRFOIL MECHANISM Original Fi le d May 51, 1933 4 Sheets-Sheet 1 r W W Aug. 29, 1939. ZAPARKA 2,170,886

AIRFOIL MEGHAN 1 SM Original Filed May 31, 1935 4 Sheets-Sheet 2 fltto lnwn v Aug. 29, 1939. E. F. ZAPARKA AIRFOIL MECHANISM 4 She'is-Sheet 5 Original Filed 'May 51, 1935 Aug. 29, 1939. E. F. ZAPARKA AIRFOIL MECHANISM Original Filed May 31, 1933 4 Sheets-Sheet 4 A76 f/a. 61

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010,430. Flam/am Patented Aug. 29, 1939 UNITED STATES PATENT OFFICE AIRFOIL MECHANISM Application May 31, 1933, Serial No. 673,730

. Renewed December 19, '1936 11 Claims.

My invention relates to airplanes, and more particularly to operating mechanisms for moving wing flaps or similar constructions into their operative and inoperative positions.

5. An object of my invention is to provide a means for stored energy on the plane which will permit the wing flaps to be quickly moved from inoperative to operative position.

Afurther object of my invention is to control the movement of the flaps so that their motion can be arrested at any desired point in their travel from operative to inoperative position.

Yet another object of my invention is topmvide means for controlling the operation of an electric or other motor carried on the plane so that the source of electrical energy flowing to the motor shall be cut off adjacent the limit points of movement of the flap mechanism. 7

While I have shown in the drawings certain embodiments of the invention, these embodiments are but examples, and I do not desire that my claims be limited to the exact showings made.

7 In the drawings? Figure 1 is a perspective view of an airplane having wing flaps and my aileron constructions;

Fig. 2 is a detail view of the fuselage, with parts broken away to show the ratchet handle for the spring power type of flap operating mechanism;

Fig. 3 is a side view partly in section of a wing tip showing the position of the flap operating parts; the flap being shown in dotted lines in the down position;

Fig. 4 is a detail top plan view of the flap oper- 35 ating mechanism for one of the wings, parts being broken away to show the construction;

Fig. 5 is a detail view of the spring power mechanism for operating the flaps, parts being shown in section to indicate the construction;

40 Fig. 6 is a view taken along the line 6-6 of Figure 5, looking in the direction of the arrows;

Fig. '7 is a view taken along the line 1-1 of Figure 5, looking in the direction of the arrows;

Fig. 8 is a detail view of a modification employing electric power to operate the wing flaps;

Fig. 9 is a schematic view showing the wiring diagram for the form of invention illustrated in Figure 8. I

Referring to the drawings, Figures 1 to 7 in- 50 elusive, I have shown an airplane having a fuselage I, wings 2, empennage control surfaces which I have designated generally by the numeral 3, ailerons 4 mounted above the wings, and wing flaps 5. r

The ailerons 4 are mounted on horns 6, and

operated by aileron control rods 1 which are at-' tached to horns 8 mounted on the ailerons. The mechanism for operating the ailerons and their principle of operation has been fully described by me in other co-pending applications, such as my application Serial No. 653,918.

The wing flaps 5 may be of the type whose trailing edge in all positions of extension or retraction lies within the locus of perpendiculars to t he datum lines of the wing sections which 10 pass through the trailing edge of the wing. It is obvious, however, that other types of wing flaps may be used. The mechanisms which I have shown for the operation of wing flaps may be adapted to other types.

The principles of operation of the ailerons 4 and the wing flaps 5 are given in my co-pending application Serial No. 657,134, where the mutual interaction of these elements is clearly expanded.

The flaps 5 are adapted to be operated by the rotation of a shaft 9 which carries a bevel gear H which meshes with a bevel gear [2. Thebevel gear [2 is carried on a shaft l3 suitably journaled in a support M which is attached to the interior of the airplane construction. The mechanism for rotating the shaft l3 will be later described.

The mechanism for operating the wing flaps 5 upon rotation of the shaft 9 will now be described.

,The shaft 9 is provided with gimbal joints l5 which permit transmission of torque and also permit free movement in all planes. The gimbal joints I5 carry shafts l6 which are provided with screw-threaded sections II. In screw-threaded engagement with the portions ll of the shafts I6 are operating heads l8 to which are pivoted at I9 operating rods 2|, which are adapted to operate remote stations in the wings for effecting movement of the flaps.

The operating heads 18 carry pivots 22 to which are pivoted forked arms 23 of bell crank levers 24 which are pivoted at the angle ,of the bell crank arms to pins 25 which are anchored in a triangular box-like support construction 26 which has triangular sides 21 with holes 28 cut away in them to lighten the construction. The 5 triangular box-like members are provided with three side pieces. One side piece 29 has no aperture in it. Another side piece 3| is provided with an'aperture or slot 32, and another side piece 33 is provided with another slot or aperture 34. The bell crank levers 24 have other arms 35 which carry pivot pins 36 at their ends over which fit links 38 The other end of the links 38 are pivoted at 39 to connecting members 4| which are attached to the flap construction.

The linkages described are the same for various flap operating stations on the wings. The stations most adjacent to the gimbal joints II have the arms 23 of the bell crank levers 24 attached di rectly to the operating heads l8 which are on the screw-threaded portions I! of the shafts I. The stations most remote from the gimbal joints l5 have the arms 23 of the bell crank levers 24 pivoted at 42 to the end of the operating links 2|, the link ends thus constituting the operating heads for these remote stations.

The shaft 9 is adapted to be rotated in either direction by a mechanism to be described. This rotation is transmitted to the shafts l8 beyond the gimbal joints l5, and through the linkages described the links 38 are'thrust either towards the rear of the wing or pulled towards the front of the wing. When the links 88 are thrust to the rear of the wings, the flaps are extended; when they are pulled towards the leading edge of the wings, the flaps are retracted. The wing flap constructions have been described in some detail in previously filed applications.

The wing flaps themselves I have designated by the numeral 48. The flaps comprise a lower smooth surface 44 having downwardly extending housing portions 45 in which are pivoted at 45 links 41, whose other ends are pivoted at 48 in the wing construction. There are provided corrugated metallic bracing members 49 having channel members 5| on their upper surface. The links 4| are pivoted to pivot pieces 52 which slide in tracks 52' on the support members. The pivots 48 for the links 41 are attached to support pieces 53 carried on the ends of support members 54 which are attached to the rear wing spar 55 by means of bolts 56. The rods 2i pass through apertures 51 formed in the support members 54 at the stations nearest the fuselage. When the links 38 are pushed to the rear, they pull on links 4| and these, through pins 52, move the flaps downward into the position shown in dotted lines in Figure 3. When the movement of the links 88 is in the opposite direction, the flaps are moved into the position shown in full lines in Figure 3. Pins 52 are attached to channel members 5i carried by the flaps.

These flaps, as hereinbefore stated, may be of the type wherein the dimensions of the flap, length of linkages and other factors are such as to cause the trailing edge of the flap to lie in positions of extension and retraction within the locus of perpendiculars drawn through the trailing edge of the wings and perpendicular to the datum lines of the wing sections. It is to be understood, however, that I am not limited to this particular type of flap in connection with the use of the operative mechanisms and systems which are described in this application. 1

In order to rotate the shaft 9 to either extend or retract the flaps, as before explained, I rotate the shaft l3. The shaft I 3 carries at its lower end a beveled gear 88. The shaft ii at its lower end is journaled at 6| ina gear casing 52. Within the casing 62 in mesh with the beveled gear 58 is a beveled gear 68. The beveled gear 68 is mounted on the end of an annular sleeve .54 which is adapted to rotate on a shaft 55, which is attached at one end to the casing 82 and which passes through a casing 58 at its other end. A spacing sleeve 81 on the shaft 95 tends to prevent play between the gears 60 and 82.

The casing 82 rests against a cover plate 58 which covers the open side of the casing 55. Mounted within the casing 55 is a spirally wound spring 89, the inner end of which is attached at H to the sleeve 84. The outer end of the spring 89 is attached by suitable rivets or otherwise, as indicated at 12, to the interior of the casing 55.

Thr sleeve 64 carries a revoluble circular plate 18 which carries a ratchet wheel 14. The ratchet wheel 14 may be made integral with the plate 13, or may be suitably attached to it. Mounted to revolve on the shart 65 is a sleeve 15 which carries a pawl lever 16. The sleeve 15 passes through an aperture made in the casing 66 and projects beyond the casing. There is attached, to the sleeve 15 an encircling collar member H which carries an operating lever 1'8 provided with a handle 19. The encircling collar 11 may be attached to the sleeve 15 by screws or any other suitable device. The shaft at its end which terminates in the casing 62 may be provided with an enlarged head to hold it in place in a suitably formed aperture in the casing 82. At its other end the shaft 85 may be screw-threaded and provided with a holding nut 8|.

The pawl lever I6 is provided with a pawl member 82 which is pivoted at 83 on the pawl lever 18. The member 82 is adapted to contact with the ratchet teeth on the ratchet wheel 74, when the handle 19 is pulled in a direction corresponding to that indicated by the arrow in Figure '7. A cam member 84 operates to hold the pawl 82 from contact with the ratchet teeth when the handle 79 is held in its off position.

The handle 19 is held in its ofi position by means of a spring 85 which is attached to a ring construction 86 suitably riveted or otherwise attached to the interior of the casing 88. The other end of the spring is attached at 81 to a lug 88 formed on the end of the pawl lever 16. When the handle 19 is pulled in the direction inddicated by the arrow in Figure 7, i. e., when the pilot seated in his seat 89 in the cockpit pulls the handle 19 towards him the pawl 82 slides off the cam 84, contacts with one of the rachet teeth on the ratchet wheel 14 and moves the ratchet wheel 74 in a clockwise direction, looking at the parts as they are indicated in Figure 6. The position of the parts in the rearmost movement of the handle 19 is indicated in dotted lines in Figure 6. The spring 85 is extended in this position and will tend to return the lever 18 and its handle 19 to the forward position, such position being indicated in dotted lines in Figure 7.

The mechanism for holding the ratchet wheel 14 in the position to which it has been advanced by the operation just described comprising a spring pressed pawl member 9! which has a downwardly projecting guide member 92 which fits within an aperture 93 formed in an extension of the casing 66, which I have indicated by the numeral 94. There is a spring 95 which bears against the interior bottom portion of this extension at one end and against .the bottom of the guide member 92, tending to hold the pawl 9| in the up position to prevent counterclockwise movement of the ratchet wheel 14, looking at the parts as shown in Figure 6. The pawl member 9| is adapted to reciprocate in guides 96 formed in the interior of the casing 68.

A release plunger 91 is provided, which is adapted to slide in an aperture formed at 98 in the casing 66. The release plunger 91 is provided with an operating button 99. The other end of the release plunger carries a cam member II which has surfaces that are adapted to bear against a roller I82 carried by the spring pressed 75 pawl member 9|. The cam member IOI slides in an aperture I03 formed in the top of the guides 96. The lower surface of the cam member is provided with a substantially horizontal surface I04, a sloping surface I05 and another substantially horizontal surface I06 having notches I01 and I06 formed therein. A latch I09 is held in an aperture III formed in one of the guides 96. A spring I I2 presses the latch I09 against the lower horizontal surface I96 of the cam member IN. The latch member I09 is adapted to ride along the surface I06 and to engage notches I01 and I08 to hold the cam member in desired positions after moving the operating button 99 to adjust the cam.

Upon pushing the operating button 99 inward, the roller I02 is operated upon by sloping cam surface I05, and the pawl member 9| is retracted downwardly against the pressure of the spring 95. This permits the spring 69 to unwind and to revolve the bevel gear 63 to extend the flap. If the operating button 99 is pushed in until the latch I09 engages the notch I08 on the surface I06, the operating'button 99 will be held in such position as to permit the spring 69 to fully unwind and to fully extend the flaps 5. However, by pulling on button 99, the cam member IOI can be moved in the opposite direction, permitting the spring 95 to push the pawl member 9I in the upward direction to engage a tooth on ratchet wheel 14 and to arrest the unwinding of the spring 69.

By suitable manipulation of the button 99, therefore, the flaps may be extended to any desired extent from the fully retracted position to their fully extended position, and the power for accomplishing the work necessary to extend the flaps is furnished by the stored energy of the spring 69.

As before explained, by operation of handle 19 of lever 18, the flaps can be rewound into their retracted position and the spring 69 coiled tightly ready to expend its force in moving the flaps into the desired operative position. In working the handle 19 back and forth, the pawl member 62 engages the ratchet teeth on wheel 14 and the wheel 14 is revolved. It is prevented from sliding backward when the handle 19 is moved in the opposite direction by the spring 85 by reason of the engagement of the pawl member 9I with the ratchet teeth. The pawl member 9I in the position of theparts shown in Figure 6 is free to slide over the surface of the ratchet teeth on ratchet wheel 14, and to be pushed into the notches formed by these teeth to prevent a counterclockwise movement of the ratchet wheel 14 when looking at that wheel from the position in which the view in Figure 6 is taken. By having the spring 69 of considerable power, the flaps can be quickly extended as needed in emergency, and the degree to which they may be extended by the spring 69 is readily controllable through the operating button 99, as just described.

Referring to Figures 8 and 9, I have shown an electrical system for operating the flaps.

In Figure 8 I have shown a detailed view which is somewhat diagrammatic, in which is mounted a motor I20 on a spar or beam I2I carried in the airplane construction. The motor is provided with a shaft I22 which carries a bevel gear I23 which meshes with the bevel gear II which operates the shaft 9 of the flap operating mechanism previously described. The shaft 9 may be journaled at I24 on the spar or beam I2I. The spar or beam I2I carries switch mechanisms I25 and I26 which have switch buttons I21 and I28,

respectively, which are adapted to contact. with a switch operating arm I29 formed as an extension of one of the arms 23 of the bell crank levers 24.

The switches 25 and 26 are automatic in operation to arrest the operation of the motor I20 when it has wound up the flap into its furthermost retracted position or extended the flap into its lowermost extended position. To control the movements of the flap in either direction and to stop them at any desired point, I have provided a hand switch It.

Referring particularly to Figure 9, I have shown the switch I 3I as comprising a bar I32 having a notch at one end I33 and a notch at the other end I34. Springs I35 at either end tend to hold the bar I32 in the position shown in Figure 9; The switch I3I is provided with terminals I36 and I31 for completing the motor circuit, and a terminal I38 for completing the solenoid circuits, as will later be described. Pivoted on the bar I32 and in contact with the terminals I36, I31 and I38 are three movable switch elements I39, MI and I42, respectively. The switch element I39 may contact within the switch with terminals I43 or I44 or 'be held in the neutral position, as indicated in Figure 9. The switch element I4I may be in contact with terminals I45 and I46, or be held in the .neutral position, as indicated in Figure 9. The switch element I42 may be in contact either with terminal I41 or I48, or be held in the neutral position, as indicated in Figure 9.

The notch element I33 of the bar I32 of the switch I3I is adapted to be engaged by a latch I49 which is pivoted at I5I and normally held in the up position by means of a spring I52. The notch I34 is adapted to cooperate with a latch I53 pivoted at I54, and normally held in the up position by means of a spring I55.

Let us assume that the mechanism in the switch I3I which is controlled by a handle I55 is so moved by the handle I56 that the bar I32 is moved to the extreme right so that latch I53 engages with notch I34 on the bar I32. This completes a circuit through a battery I51 carried on the plane, through a lead I58 to terminal I31, through switch element I42, terminal I46 through a lead I59 to a lead I6I, through a field I62 of the motor I20, through the armature of the motor back through lead I63, lead I64 to terminal I44, through switch element I39, terminal I36, lead I65, back to the battery I51. This will cause the motor I20 to move in one direction.

Let us assume that the motor has been stopped before the flap is moved either to its fully retracted or fully extended position by movement of the handle I56 so that the switch I3I occupies the neutral position shown in Figure 9. The direction of movement of the flap may be reversed by reversing the movement of the handle I56 of the switch I3I to cause connection to be made by switch element I4I with terminal I45, and by contact of the switch element I39 with terminal I43. This will cause the flap to move in the opposite direction by reversing the direction of rotation of the motor I20. The flaps can be moved in either direction by controlling the switch I3I as desired.

There is provided an automatic means to prevent overrunning of the motor and harm to the operating mechanism which comprises the switches I25 and I26..

Let us assume that motor I20 has caused the flap elements to be moved into a position such that the operating arm I29, which is attached to the arm I23 of the bell crank 24, has contacted with the button I28 of the switch I26, and closed the switch terminals. When this happens, the circuit is completed through a lead I66 to terminal I38, through switch element I42, terminal I48, lead I61, solenoid I63, lead I59, lead I53 to the battery I51. The other side of the battery is connected through lead I 1| and lead I12 back to the switch I26. Thus the solenoid I58 is energized, pulling down on latch I53 against the tension of spring I55 and releasing the notch I34 on bar I32, thus permitting the springs I35 to center the bar I32 in the off position, as indicated in'Figure 9, thus stopping the operation of the motor.

On the limiting movement of the flaps in the opposite direction the switch operating arm I29 contacts with switch button I21 and closes the circuit through switch I25, which closes the following circuit: through lead I66, terminal I33, switch element I42, terminal I41, lead I13, solenoid I14, lead I15, lead I58, to the battery I51. The other side of the battery is connected through lead I H through the switch to the lead I66, thus completing the circuit. When this occurs, the solenoid I14 is energized, pulling downwardly on latch I49 against the tension of spring I52, and releasing the contact of latch I49 in notch I33 and the switch bar I32 moves into the neutral position indicated in Figure 9, cutting off the motor and preventing overrunning thereof, and consequent possible injury to the operating parts.

With the circuits just described there is a safetyfactor introduced in the operationof the electric motor to prevent injury to the flap operating.

mechanism, which is of considerable importance when the inertia of the moving armature of the motor when rotating at high speeds is considered.

I claim: 1. An airplane construction comprising means for affecting the flow around a wing to eii'ect a change in the lift co-eflicient thereof, a source of power carried by the airplane, a screw-threaded shaft adapted to be driven by said source of power, an operating head in screw-threaded engagement with the screw-threaded portion of the shaft, bell crank linkages operated by the operating head to modify the position of the first named means and support means for the bell crank on which it is pivoted, said means formed with apertures-through which the arms of the bell crank pass.

2. A flap mechanism comprising an airplane, wings for the airplane, wing flaps for the wings, a source of power carried by the airplane, a screwthreaded shaft adapted to be-driven by the source of power, operating heads in'screw-threaded engagement with the screw threads on the shaft, bell crank linkages for each operating head to "move the flaps, and support means for the bell crank on which it is pivoted and through apertures in which the arms of the bell crank pass.

3. A flap operating mechanism comprising an airplane, wings for the airplane, wing flaps for the wings, a spring motor of sufficient power to quickly move the flaps to operative position, a screw-threaded shaft adapted to be driven by the spring motor, operating heads in screwthreaded engagement with the screw-threads on the shaft, linkages for each operating head to move the flaps, and support means for the link- 7 ages on which they are pivoted, said means formed with apertures through which the linkages pass.

4. A flap operating mechanism comprising an airplane, wings for the airplane, wing flaps for the wings, a spring motor of sufficient power to quickly move the flaps to operative position, a screw-threaded shaft adapted to be driven by the spring motor, operating heads in screw-threaded engagement with the screw-threads on the shaft, linkages for each operating head to move the flaps, trigger means to effect quick release of the spring and quick movement of the flaps into operative positions, and support means for the linkages on which they are pivoted, said means formed with apertures through which the linkages pass.

5. A flap operating mechanism comprising an airplane, wings for the airplane, wing flaps for the wings, a spring motor of suificient power to quickly move the flaps to operative position, ratchet means to coil the spring in the spring motor, a screw-threaded shaft adapted to be driven by the spring motor, operating heads in screw-threaded engagement with the screwthreads on the shaft, linkages for each operating head to move the flaps, trigger means for quick release of the spring and quick movement of the flaps into operative positions, and support means for the linkages on which they are pivoted, said means formed with apertures through which the linkages pass.

An airplane construction comprising a wing, means affecting the flow around the wing to effect a change in the lift coefficient thereof, a screw-threaded shaft, means to rotate the shaft, an operating head in screw-threaded engagement with the screw-threaded portion of the shaft, bell crank linkages lying between the wing surfaces operated by the operating head to modify the position of the first named means, and support means for the.bell crank on which it is pivoted, said means formed with aperture through which the arms of the bell crank pass.

7. A flap mechanism comprising an airplane, wings for the airplane, wing flaps for the airplane, a screw-threaded shaft adapted to be driven, operating heads in screw-threaded engagement with the screw threads on the shaft, bell crank linkages for each operating head to move the flaps, said bell cranks lying between the surfaces of the wing and having their thinness lying substantially parallel to the wing chords, and support means for the bell crank on which it is pivoted, said means formed with apertures through which the arms of the bell crank pass.

8. In an operating mechanism for a wing flap, an operating head, means to reciprocate the operating head, a bell crank lever having one arm attached to the operating head, the plane of the arms being approximately parallel to the wing chord, a link pivoted to the other arm of the bell crank lever and to the wing flap to move the latter, and a triangular box-like bracing means having apertures through which the arms of the bell crank lever extend.

9. In an operating mechanism for a wing flap, a plurality of flap operating stations for the flap, an operating head for each operating station, a coinmon means to reciprocate the plurality of operating heads, a bell crank lever at each operat ing station having one arm thereof attached to an operating head, means at each operating station driven by the other arm of the bell crank to move the flap, and a plurality of box-like bracing means having apertures in the sides through which the arms of each bell crank lever extend.

10. In an operating mechanism for a wing flap,

a plurality of flap operating stations. an operating head at each station, means located at each station for reciprocating the operating head, bell crank levers at each operating station, the plane of the arms of which is substantially parallel to the wing chord, each bell crank having one arm attached to the operating head for that station, a link at each operating station pivoted to the other arm of the bell crank to move the wing flap, and a plurality of box-like bracing means having apertures in the sides through which the arms or each bell crank lever extend.

11. In an operating mechanism for a wine flap an operating head. meansto reciprocate the operating head, a bell crank lever having one arm attached to the operating head and mounted with its pivot approximately at right angles with the wing chord, means driven by the other arm of the bell crank lever to move the wing flap, and triangular box-likebracing means through the sides or which the arms of the bell crank lever 

